Re: Smart/Dumb box again...

Dave,

200 bytes? To do what? My keyboard interrupt to get cursor keys fast
is longer then that! We should all go back to VIC-20! ;>)

Seriously, You'd have to send "packets" of XYZ move commands in steps,
(avoids parse), step the axis, delay to make feed speed come out
correctly. Check for limit switches etc., signal problems. The packets
would have to be "queued up". Yes, and it's been done! Check out
FlashCut!

But why take up an entire PC, when a dedicated '386 or '486 "controller"
board, with code in EPROM could do it just as well
(better/smaller/faster/etc.)! Let's program that!

Alan KM6VV


dkowalcz@... wrote:

>
> To all,
>
> Had a thought today (dangerous, I know..!) Back to that black box
> we were discussing a month or two ago...
>
> Instead of using special hardware - how about, say, running a tight
> assembler program on an old 386 or 486 PC to do two things:
>
> - Read tokenized commands from the COM port
> - Control steppers, limit switches on the parallel port
>
> This way, whatever's running the interpreter can just send very
> general commands to the "workhorse" computer that takes care of the
> rest and handshakes when it's done.
>
> Some back of the envelope figuring tells me that smooth pulses up
> to about 500kHz should be pretty easy to achieve, hooking interrupts
> and such of course. I was surprised this week to find that my old
> VIC-20 driven servo controller ran in about 200 bytes of assembly
> language.
>
> Seemed like more at the time, you know? :) Anyway, that set me to
> thinking about what could be realizable with the more modern junk and
> some sharp programming. Any thoughts?
>
> Dave Kowalczyk
> Ames IA